Was it simply because he didn't get any contract offers, or does he just not want to continue? Seems a bit pessimistic to me to stop your career at 24-year-old just because you don't have a contract in September.
In the Feltet interview it sounded like an extension with Uno-X had been his main target and thet he hadn't actively pursued a contract anywhere else, which obviously also made it less likely that he would receive an offer from other teams.
Since Uno-X have signed other riders, he has been let go, but it seems like he isn't too bothered by their decision and is ready to move on.

Stopper karrieren: 24-årig dansk prof siger farvel
I en alder af 24 år har danske Morten Hulgaard (Uno-X Pro Cycling Team) besluttet at indstille sin cykelkarriere.